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In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

Labor, coalition clash over AAA ratings

The federal government says Australia's top line credit ratings are secure and has reaffirmed its commitment to return the budget to surplus in the medium term.

Treasurer Wayne Swan was responding to reports credit rating agency Standard & Poor's (S&P) had warned the triple-A rating could be at risk if the government did not demonstrate its commitment to "prudent fiscal policy".

"Our medium term fiscal strategy is to deliver surpluses on average over the cycle, an approach which has consistently underpinned our AAA rating," Mr Swan and finance minister Penny Wong said in a joint statement.

Labor has dropped a forecast surplus for this financial year, ahead of the May budget.

Expectations are for a deficit of up to $10 billion, and there's a chance future projected surpluses could also be eroded.

Shadow treasurer Joe Hockey said Labor had put Australia's ratings at risk by not showing a clear commitment to eliminate the budget deficit and paying down debt.

"If Australia is downgraded again because of what Labor has done, then every Australian will pay a heavy price because it will flow through to every household in increased banking costs and increased charges," he told Sky News on Wednesday.

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"We were the ones that claimed back Australia's triple-A rating previously, we will do it if we need to again if Labor loses it."

Australia is rated triple-A by all three ratings agencies - S&P, Moody's Investors Service and Fitch Ratings - and it's one of only eight countries to boast such a high ranking.

Fitch Ratings gave Australia a triple-A ranking in November 2011, four years after Labor won power.

"How shadow treasurer Joe Hockey can commit to a AAA rating from all three agencies when the Liberals had 11 years to achieve it - and failed (to do) so - is laughable," Mr Swan said.

"Australia's public finances are among the very strongest in the world, with net debt just a fraction of (that of) other countries."

Opposition Leader Tony Abbott said there needed to be a clear path to return to surplus and the coalition was best placed to achieve this if it won government in September.

"We shouldn't think our economic future is assured unless we see from the national government a clear path to economic responsibility," he told reporters in Melbourne.

"Surpluses are in our DNA."

Mr Swan is due to hand down his sixth budget on May 14.

Meanwhile, Prime Minister Julia Gillard on Wednesday declined to respond to budget speculation, including suggestions of an increase in the Medicare levy to pay for the national disability insurance scheme.